#!/bin/bash

# by Andy Maloney
# http://asmaloney.com/2013/07/howto/packaging-a-mac-os-x-application-using-a-dmg/

makepack() {
  # make sure we are in the correct dir when we double-click a .command file
  dir=${0%/*}
  if [ -d "$dir" ]; then
    cd "$dir"
  fi

  # set up your app name, version number, and background image file name

  APP_NAME=$1
  VERSION=$2
  DMG_BACKGROUND_IMG=$3

  # you should not need to change these
  APP_EXE="${APP_NAME}.app/Contents/MacOS/${APP_NAME}"

  VOL_NAME="${APP_NAME} ${VERSION}"   # volume name will be "SuperCoolApp 1.0.0"
  DMG_TMP="${VOL_NAME}-temp.dmg"
  DMG_FINAL="${VOL_NAME}.dmg"         # final DMG name will be "SuperCoolApp 1.0.0.dmg"
  STAGING_DIR="./Install"             # we copy all our stuff into this dir

  # Check the background image DPI and convert it if it isn't 72x72
  _BACKGROUND_IMAGE_DPI_H=`sips -g dpiHeight ${DMG_BACKGROUND_IMG} | grep -Eo '[0-9]+\.[0-9]+'`
  _BACKGROUND_IMAGE_DPI_W=`sips -g dpiWidth ${DMG_BACKGROUND_IMG} | grep -Eo '[0-9]+\.[0-9]+'`

  if [ $(echo " $_BACKGROUND_IMAGE_DPI_H != 72.0 " | bc) -eq 1 -o $(echo " $_BACKGROUND_IMAGE_DPI_W != 72.0 " | bc) -eq 1 ]; then
    echo "WARNING: The background image's DPI is not 72.  This will result in distorted backgrounds on Mac OS X 10.7+."
    echo "         I will convert it to 72 DPI for you."

    _DMG_BACKGROUND_TMP="${DMG_BACKGROUND_IMG%.*}"_dpifix."${DMG_BACKGROUND_IMG##*.}"

    sips -s dpiWidth 72 -s dpiHeight 72 ${DMG_BACKGROUND_IMG} --out ${_DMG_BACKGROUND_TMP}

    DMG_BACKGROUND_IMG="${_DMG_BACKGROUND_TMP}"
  fi

  # clear out any old data
  rm -rf "${STAGING_DIR}" "${DMG_TMP}" "${DMG_FINAL}"

  # copy over the stuff we want in the final disk image to our staging dir
  mkdir -p "${STAGING_DIR}"
  cp -rpf "${APP_NAME}.app" "${STAGING_DIR}"
  # ... cp anything else you want in the DMG - documentation, etc.

  pushd "${STAGING_DIR}"

  # strip the executable
  echo "Stripping ${APP_EXE}..."
  strip -u -r "${APP_EXE}"

  # compress the executable if we have upx in PATH
  #  UPX: http://upx.sourceforge.net/
  if hash upx 2>/dev/null; then
    echo "Compressing (UPX) ${APP_EXE}..."
    upx -9 "${APP_EXE}"
  fi

  # ... perform any other stripping/compressing of libs and executables

  popd

  # figure out how big our DMG needs to be
  #  assumes our contents are at least 1M!
  SIZE=`du -sh "${STAGING_DIR}" | sed 's/\([0-9\.]*\)M\(.*\)/\1/'` 
  SIZE=`echo "${SIZE} + 1.0" | bc | awk '{print int($1+0.5)}'`

  if [ $? -ne 0 ]; then
    echo "Error: Cannot compute size of staging dir"
    exit
  fi

  # create the temp DMG file
  hdiutil create -srcfolder "${STAGING_DIR}" -volname "${VOL_NAME}" -fs HFS+ \
    -fsargs "-c c=64,a=16,e=16" -format UDRW -size ${SIZE}M "${DMG_TMP}"

  echo "Created DMG: ${DMG_TMP}"

  # mount it and save the device
  DEVICE=$(hdiutil attach -readwrite -noverify "${DMG_TMP}" | \
    egrep '^/dev/' | sed 1q | awk '{print $1}')

  sleep 2

  # add a link to the Applications dir
  echo "Add link to /Applications"
  pushd /Volumes/"${VOL_NAME}"
  ln -s /Applications
  popd

  # add a background image
  mkdir /Volumes/"${VOL_NAME}"/.background
  cp "${DMG_BACKGROUND_IMG}" /Volumes/"${VOL_NAME}"/.background/

  # tell the Finder to resize the window, set the background,
  #  change the icon size, place the icons in the right position, etc.
  echo '
  tell application "Finder"
  tell disk "'${VOL_NAME}'"
  open
  set current view of container window to icon view
  set toolbar visible of container window to false
  set statusbar visible of container window to false
  set the bounds of container window to {400, 100, 920, 440}
  set viewOptions to the icon view options of container window
  set arrangement of viewOptions to not arranged
  set icon size of viewOptions to 72
  set background picture of viewOptions to file ".background:'${DMG_BACKGROUND_IMG}'"
  set position of item "'${APP_NAME}'.app" of container window to {160, 205}
  set position of item "Applications" of container window to {360, 205}
  close
  open
  update without registering applications
  delay 2
  end tell
  end tell
   ' | osascript

   sync

   # unmount it
   hdiutil detach "${DEVICE}"

   # now make the final image a compressed disk image
   echo "Creating compressed image"
   hdiutil convert "${DMG_TMP}" -format UDZO -imagekey zlib-level=9 -o "${DMG_FINAL}"

   # clean up
   rm -rf "${DMG_TMP}"
   rm -rf "${STAGING_DIR}"

   echo 'Done.'

   exit
}
